Effect of Fire on Flowering and Fruiting of Anacardium Humile (Anacardiaceae) in Cerrado Stricto Sensu

Abstract

Knowledge about the effects of fire on sexual reproduction of Cerrado woody species is fundamental for elaborating public policies and management plans for its conservation. The present study evaluated the effect of a controlled burning on flowering and fruiting of Anacardium humile in an Cerrado stricto sensu environment, in Cavalcante, GO. An area with no fire records for five years was submitted to controlled burning in May 2016, used as the experimental area and its adjacent areas protected from fire as control area. In each area, 16 reproductive individuals were selected and their production of floral buds, flowers and fruits, followed up for 17 months. In 2016 the production of reproductive structures was higher in the control area, since the majority of individuals of the burned area invested in the recovery of vegetative structures (branches) damaged by fire. Only three individuals flowered in the burned area in 2016 and presented greater effort in the production of buds and flowers per panicle than the individuals in the control area, however, the fruit set was equal between the areas. One year after fire, the production of reproductive structures became equal between areas. The control area presented higher fruit production in 2017 in comparison to 2016, indicating a variable pattern in annual fruit production. The impact of fire on the reproductive structures of A. humile is greater in the same year of fire and its reproductive potential can be normalized in the subsequent year.

Fire‐triggered flowering is the dominant post‐fire strategy in a tropical savanna

“…Quantifying PFF at the community scale is less conducted in savannas than in other regions, and most observations have been made for single, mainly shrub, species (Franceschinelli & Bawa, 2005; Conceição & Orr, 2012; de Sousa & da Cunha, 2018; Dodonov et al, 2018; Shearman et al, 2019, but see Massi et al, 2017; Pilon et al, 2018). In Lamont and Downes’ (2011) review of PFF in Australasia and South Africa, the vast majority of species identified as having this strategy (>70%) were from mediterranean climate regions, whereas only ~14% were from savanna.…”

Structural assessment of a population of Anacardium humile subjected to fire during different periods of the year

“…Anacardium humile has a low potential for sexual reproduction (Carvalho et al 2005). In 2016, the fruit production by the studied population was low (Sousa & Cunha 2018b). Therefore, we believe that natural regeneration had a low contribution to the abundance observed in the LF area.…”

“…The presence of xylopodium provides protection and resistance to fire and drought (Agostini-Costa et al 2016), which makes it frequent in burned environments (Loiola et al 2010). In the territory of the Kalunga, the flowering occurs between May and September, with fruiting occurring from July to September (Sousa & Cunha 2018b). The high ratio of 4:1 between male and hermaphrodite flowers (Almeida et al 1998), the inability of some hermaphrodite flowers to turn into fruits, the tendency of stamen pollen grains to remain attached to the anther after dehiscence, and the existence of only one fertile stamen in the staminate flowers are mentioned as reasons for its poor pollination (Ferrão 1995).…”

“…al. 2010;Palermo & Miranda 2012;Françoso et al 2014;Deus et al 2016;Sousa & Cunha 2018b), seed banks and dispersal (Cirne & Miranda 2008;Xavier 2011), recruitment and mortality rates of many species (Medeiros & Miranda 2005;Bouchartdet et al 2015), and the size and distribution of regrowth (Silva et al 2009;Dodonov et al 2014), especially in dryer months (Sato 2003). The short intervals between fires prevent seedling development and recruitment, and successive regrowth results in depletion of storage organs (Whelan 1995;Medeiros 2002).…”

Fire seasonality plays a limited role in the reproduction of Anacardium humile A. St.‐Hil. in a tropical savanna

“…This continuous effect leads to changes in the seed bank and seed dispersal (Cirne & Miranda 2008) as well as plant species' recruitment and mortality rates (Medeiros & Miranda 2005;Bouchartdet et al 2015). Therefore, the marked effects of anthropogenically altered burning frequencies on different plant species populations can alter the community as a whole (Whelan 1995).…”